- CyDEPMPOs: A class of stable cyclic DEPMPO derivatives with improved properties as mechanistic markers of stereoselective hydroxyl radical adduct formation in biological systems
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The cis/trans diastereoisomeric composition of hydroxyl radical adducts to chiral cyclic nitrones can be used to approach mechanisms of free radical formation in biological systems. Such determination is greatly simplified when both diastereoisomers have ESR spectra with at least two non-overlapping lines. To achieve this prerequisite, a series of DEPMPO-derived spin traps bearing one unsubstituted or alkyl-substituted 2-oxo-1,3,2-dioxaphosphorinane ring were synthesized and their structures were confirmed by X-ray diffraction, 1H, 13C and 31P NMR. These CyDEPMPOs nitrones showed variable lipophilicities and LD50 values on murine fibroblasts compatible with a safe use in biological spin trapping. All CyDEPMPOs formed persistent spin adducts with a series of free radicals, including superoxide and hydroxyl (i.e., CyDEPMPOs-OH) and the in vitro half-life times of these two latter were at least as extended as those of parent DEPMPO. Using four methods of CyDEPMPOs-OH formation, the cis-CyDEPMPOs-OH percentage was found significantly varied with substitution on the P-containing ring and, more interestingly, with the generating system.
- Gosset, Ga?lle,Clément, Jean-Louis,Culcasi, Marcel,Rockenbauer, Antal,Pietri, Sylvia
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- Phosphorus-nitrogen-containing polyether polyol compound as well as preparation method and application thereof
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The invention discloses a phosphorus-nitrogen-containing polyether polyol compound as well as a preparation method and application thereof. The phosphorus-nitrogen-containing polyether polyol compound is selected from any one of substances with a structural formula shown in a formula I in the specification. The compound is used as a phosphorus-nitrogen-containing polyether polyol synergistic flame retardant, the compound is used as a reactive phosphorus-nitrogen-containing polyether polyol and can chemically react with isocyanate to generate a carbamate group, flame-retardant elements phosphorus and nitrogen are introduced into a polyurethane network in the form of covalent bonds, and the phosphorus-nitrogen-containing polyether polyol with excellent flame-retardant performance is prepared. The problem that an additive flame retardant is easy to separate out and migrate in the prior art is solved, and excellent flame resistance is achieved.
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Paragraph 0196-0199
(2021/06/06)
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- Herbicidal activity and application cyclic of phosphonates
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Among alkylphosphonates Io,O,O-dimethyl 1-(2,4-dichlorophenoxyacetoxy) ethylphosphonate (clacyfos) was found to be an effective inhibitor against dicotyledons PHDc and exhibited excellent herbicidal activity in our previous work. According to our study on the alkylphosphonates Io, both R1 and R2 groups in the structural unit of phosphorus-containing played a very important role in herbicidal activity. Therefore, a series of 2-[1-(substituted phenoxycarboxy)alkyl]-5,5-dimethyl-1,3,2-dioxaphosphinane-2-one containing fluorine II was obtained by the modification of alkylphosphonates Io. The bioassay results showed that cyclic phosphonate II-6 with CH3 as R, 2-Cl,4-F as Yn exhibited promising herbicidal activity. Its herbicidal activity, weed-controlling spectrum, selectivity between crops and weeds were further evaluated in greenhouse and field.
- He,Wang,Peng,Tan
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p. 510 - 512
(2018/12/04)
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- Design, synthesis and herbicidal activity of novel cyclic phosphonates with diaryl ethers containing pyrimidine
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Thirteen novel cyclic phosphates were rationally designed and synthesized by introducing diary ethers containing pyrimidine. All the target compounds were characterized by 1H, 13C, 31P NMR and HRMS. The test of herbicidal activity indicated that most of the compounds showed good herbicidal activities against Amaranthus retroflexus. The compounds IA-2 (1-(5,5-dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)propyl-2-((4,6-dimethoxypyrimidin-2-yl)oxy)benzoate) and IA-3 ((5,5-dimethyl-2-oxido-1,3,2-dioxaphosphinan-2-yl)(phenyl)methyl-2-((4,6-dimethoxypyrimidin-2-yl)oxy)benzoate) exhibited remarkable post-emergency herbicidal activity against the tested monocotyledonous weed at the dosage of 112.5 g ai/ha.
- Zhang, Shasha,Guo, Xinjuan,Zhou, Yuan,Yang, Yalan,Peng, Hao,He, Hongwu
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supporting information
p. 1158 - 1163
(2019/07/04)
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- Synthesis and herbicidal activity of α-[(substituted phenoxybutyryloxy or valeryoxy)]alkylphosphonates and 2-(substituted phenoxybutyryloxy)alkyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one containing fluorine
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Based on our previous work on the structural modification of the lead compound I, three series of novel fluorine-containing phosphonates derivatives (II, III and IV) were designed and synthesized. Their post-emergence herbicidal activities against some species of weeds were evaluated in a green house. The compounds II were synthesized by introducing of two methylene into the structure I. Compared with the commercial herbicidal clacyfos, compounds II showed moderate herbicidal activity with 60–85% inhibition effect against chingma abutilon (Abutilon theophrasti), common amaranth (Amaranthus retroflexus) and white eclipta (Eclipta prostrate) at a rate of 150 g ai/ha. The compounds III were designed by introducing open-chain phosphonates, which displayed notable herbicidal activity. Especially, the compounds III-1–III-4, III-6, III-8, III-11 and III-12 exhibited significant herbicidal activity (80–100%) comparing to the clacyfos against all tested broadleaf weeds, while compounds IV with five carbon atoms in the carboxylic acid chain were inactive against all of the tested weeds. Structure-activity relationship analyses indicated that the length of the carbon chain had a great effect on the herbicidal activity. Furthermore, a broad spectrum test confirmed that compounds III-4 and III-8 were comparable with glyphosate against all of the tested weeds at a rate of 75 g ai/ha.
- Wang, Wei,Zhou, Yuan,Peng, Hao,He, Hong-Wu,Lu, Xing-Tao
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- Synthesis and Solubility of 5,5-Dimethyl-2-(phenyl(phenylamino)methyl)-1,3,2-dioxaphosphinane 2-oxide in Selected Solvents between 278.15 K and 347.15 K
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A flame retardant with enhanced phosphorus-nitrogen content, 5,5-dimethyl-2-(phenyl(phenylamino)methyl)-1,3,2-dioxaphosphinane 2-oxide (DPPO), was synthesized by the reaction of 5,5-dimethyl-1,3,2-dioxaphosphinane 2-oxide (DDPO) with N-benzylideneaniline. The structure of DPPO was characterized by nuclear magnetic resonance (1H NMR and 31P NMR) and Fourier transform infrared (FT-IR) spectroscopy. The thermal stability of DPPO was characterized by thermogravimetric analysis (TGA). The solubilities of DPPO were measured in different solvents including ethyl acetate, methanol, chloroform, acetonitrile, acetone, 1,2-dichloroethane, 1,4-dioxane, dichloromethane, tetrachloromethane, benzene, tetrahydrofuran, and isopropanol at temperature ranging from 278.15 to 347.15 K by the gravimetrical method. The mole fraction solubilities of DPPO in the above-mentioned organic solvents were correlated as the Apelblat equation, and the calculated values with equations shows good consistency with the experimental values. The root-mean-square deviation was less than 0.1%, and the average relative error was less than 0.04 in all of the experiments.
- Ma, Xiao,Zhao, Qianqiong,Liu, Qianwen,Xing, Yalin,Fan, Ruilan,Tian, Rongkai
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p. 4196 - 4204
(2017/12/26)
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- Reaction of allenylphosphonates/allenylphosphine oxides with thiocyanates/isothiocyanates or oxalyl chloride/AgNO3
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In this paper, we describe thiocyanation as well as chlorination of selected allenylphosphonates/allenyl phosphine oxide, using ammonium thiocaynate or (OCH2CMe2CH2O)PNCS (for thiocyanation) or oxalyl chloride/AgNO3/
- Swamy, K. C. Kumara,Chakravarty, Manab,Debnath, Shubham,Reddy, M. Nagarjuna
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p. 763 - 768
(2017/06/05)
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- METHOD FOR THE SYNTHESIS OF HETEROCYCLIC HYDROGEN PHOSPHINE OXIDE
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The present invention is related to a method for the synthesis of a heterocyclic hydrogen phosphine oxide, having the general formula (I), wherein: - R is a aliphatic or aromatic divalent group optionally comprising one or more heteroatoms and optionally comprising one or more substituents and - X and Y are independently selected from -O-, -C(O)O- and -NR'- wherein R' is a monovalent group optionally comprising one or more heteroatoms comprising the steps of: a) forming a reaction mixture by mixing a compound having the general formula HX-R-YH and tetraphosphorus hexaoxide; b) recovering the resulting compound comprising the heterocyclic hydrogen phosphine oxide.
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Paragraph 0058
(2016/03/13)
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- Synthesis and Herbicidal Activity of α-(Substituted Phenoxybutyryloxy or Valeryloxy)alkylphosphonates and 2-(Substituted Phenoxybutyryloxy)alkyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one
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On the basis of our work on the modification of alkylphosphonates 1, a series of α-(substituted phenoxybutyryloxy or valeryloxy)alkylphosphonates (4-5) and 2-(substituted phenoxybutyryloxy)alkyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one (6) were designed and synthesized. The bioassay results indicated that 14 of title compounds 4 exhibited significant postemergence herbicidal activity against velvetleaf, common amaranth, and false daisy at 150 g ai/ha. Compounds 5 were inactive against all tested weeds. Compounds 6 exhibited moderate to good inhibitory effect against the tested dicotyledonous weeds. Structure-activity relationship (SAR) analyses showed that the length of the carbon chain as linking bridge had a great effect on the herbicidal activity. Broad-spectrum tests of compounds 4-1, 4-2, 4-9, 4-30, and 4-36 were carried out at 75 g ai/ha. Especially, 4-1 exhibited 100% inhibition activity against the tested dicotyledonous weeds, which was higher than that of glyphosate.
- Wang, Wei,Zhang, Sha-Sha,Zhou, Yuan,Peng, Hao,He, Hong-Wu,Lu, Xing-Tao
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p. 6911 - 6915
(2016/10/03)
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- PROCESS OF PREPARING CYCLIC PHOSPHONATE ESTER, CYCLIC PHOSPHONATE ESTER PREPARED THEREFROM AND INDUSTRIAL APPLICATIONS CONTAINING THE SAME
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There is provided herein a process for preparing cyclic phosphonate ester comprising reacting a glycol with at least one of phosphonic acid and phosphinic acid in the presence of a solvent. There is also provided a flame retardant comprising the cyclic phosphonate ester and industrial applications containing a flame retardant effective amount of the cyclic phosphonate ester.
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Paragraph 0054
(2015/11/17)
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- P(=O)H to P-OH Tautomerism: A Theoretical and Experimental Study
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Phosphinylidene compounds R1R2P(O)H are important functionalities in organophosphorus chemistry and display prototropic tautomerism. Quantifying the tautomerization rate is paramount to understanding these compounds' tautomerization behavior, which may impact their reactivities in various reactions. We report a combined theoretical and experimental study of the initial tautomerization rate of a range of phosphinylidene compounds. Initial tautomerization rates are found to decrease in the order H3PO2 > Ph2P(O)H > (PhO)2P(O)H > PhP(O) (OAlk)H > AlkP(O)(OAlk)H ≈ (AlkO)2P(O)H, where "Alk" denotes an alkyl substituent. The combination of computational investigations with experimental validation establishes a quantitative measure for the reactivity of various phosphorus compounds, as well as an accurate predictive tool.
- Janesko, Benjamin G.,Fisher, Henry C.,Bridle, Mark J.,Montchamp, Jean-Luc
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supporting information
p. 10025 - 10032
(2015/11/03)
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- Synthesis and biological evaluation of α-hydroxyalkylphosphonates as new antimicrobial agents
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A set of α-quaternary 3-chloro-1-hydroxyalkylphosphonates, analogues of fosfomycin and fosfonochlorin, some of which are new compounds, was synthesized. The compounds were screened for bioactivity against several clinical and standard microbial isolates. Some were found to have moderate activity. The activity was higher with phenyl protection of the phosphoryl ester groups and α-phenyl substitution. Compound 11 was as effective or more potent than fosfomycin or chloramphenicol against several Gram-negative bacteria as well as against some Gram-positive ones.
- Faísca Phillips, Ana Maria,Barros, Maria Teresa,Pacheco, Marta,Dias, Ricardo
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supporting information
p. 49 - 53
(2014/01/17)
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- Synthesis and herbicidal activity of 2-(Substituted phenoxyacetoxy)alkyl-5, 5-dimethyl-1,3,2-dioxaphosphinan-2-one
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A series of 2-(substituted phenoxyacetoxy)alkyl-5,5-dimethyl-1,3,2- dioxaphosphinan-2-ones IIa-s were designed and synthesized on the basis of the previous work for the modification of alkylphosphonates I, and their structures were confirmed by 1H NMR, 31P NMR, 13C NMR, IR, MS, and elemental analysis. Their herbicidal activities against seven species of weeds were evaluated in a greenhouse. A part of the title compounds such as IIa-g, IIk, IIo, and IIr exhibited significant postemergence herbicidal activity against Abutilon theophrasti, Brassica juncea, Amaranthus retroflexus, and Eclipta prostrate at a dosage of 150 g ai/ha. Structure-activity relationship analyses indicated that the introduction of a phosphorus-containing heterocyclic ring had a favorable effect on herbicidal activity, and their herbicidal activity could be further increased by a reasonable combination of X, Y, and R in parent structure II. It could be found that the title compounds IIa 2-[(2,4-dichlorophenoxy)acetoxy](methyl)methyl-5,5-dimethyl-1,3, 2-dioxaphosphinan-2-one and IIr 2-[(4-chloro-2-methyl-phenoxy)acetoxy](methyl) methyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one possess high activity and a broad spectrum against all of the test broadleaf weeds with 70-100% inhibition effect at a dosage of 75 g ai/ha, and the title compounds IIa and IIr are safe for corn and wheat at a dosage of 150 g ai/ha. Furthermore, the title compound IIa possesses low rat toxicity. These results suggest that the title compounds IIa and IIr could be potential and selective postemergence herbicides for further development.
- Wang, Wei,He, Hong-Wu,Zuo, Na,He, Hai-Feng,Peng, Hao,Tan, Xiao-Song
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scheme or table
p. 7581 - 7587
(2012/10/08)
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- Synthesis and herbicidal activity of 2-(substituted phenoxyacetoxy)alkyl-5, 5-dimethyl-1,3,2-dioxaphosphinan-2-one containing fluorine
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A series of novel 2-(substituted phenoxyacetoxy)alkyl-5,5-dimethyl-1,3,2- dioxaphosphinan-2-one bearing fluorine 5a-n and fluorine free 5o-q were designed and synthesized. The results of bioassay showed that some of the target compounds exhibited excellent herbicidal activities to Abutilon theophrasti, Brassica juncea, Amaranthus retroflexus and Eclipta prostrata in post-emergence treatment at a dosage of 150 g ai/ha. It could be found that the type and position of fluorine-containing group as X or Y on benzene ring had a very important effect on herbicidal activity. Compound 5l 2-[(2-chloro-4- fluorophenoxy)acetoxy](methyl)methyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one showed notable herbicidal activity, with 100% inhibition against A. theophrasti and A. retroflexus; and compound 5m 2-(3-trifluoromethylphenoxyacetoxy)(methyl) methyl-5,5-dimethyl-1,3,2-dioxaphosphinan-2-one with 100% inhibition against A. theophrasti even at a dosage of 75 g ai/ha. Additional crop selectivity testing showed that compounds 5g 2-(3-trifluoromethylphenoxyacetoxy)(phenyl)methyl-5,5- dimethyl-1,3,2-dioxaphosphinan-2-one and 5l are safe to rice, corn, cotton, rape and wheat.
- Wang, Wei,He, Hong-Wu,Zuo, Na,Zhang, Xin,Lin, Ji-Sheng,Chen, Wei,Peng, Hao
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- PHOSPHORUS-CONTAINING COMPOUNDS AND POLYMERIC COMPOSITIONS COMPRISING SAME
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Phosphorus-containing compounds of formula (I): (I) wherein m, n, R, R1 and R2 are as set forth in the claims. The compounds of formula (I) can be used to provide polymers with flame retardant properties.
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Page/Page column 28
(2010/04/06)
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- ORGANOPHOSPHORUS COMPOUND HAVING PHOSPHATE-PHOSPHONATE BOND, AND FLAME-RETARDANT POLYESTER FIBER AND FLAME-RETARDANT POLYURETHANE RESIN COMPOSITION EACH CONTAINING THE SAME
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The present invention provides a phosphate-phosphonate compound which has a low volatility and a high phosphorus content, does not exert adverse influences on the physical properties of a product containing the phosphate-phosphonate compound as a material, and is recyclable and causes substantially no environmental load since a halogen atom such as a chlorine atom or a bromine atom is not included. A phosphorus compound containing a phosphate-phosphonate bond in one molecule and having a specific structure has a high flame retarding property. By using a phosphate-phosphonate compound as a flame retarding agent for a polyurethane or for a polyester, preferable plasticity and flame retarding property are obtained. Such a flame retardant agent exerts substantially no adverse influences on the physical properties of a polyurethane foam or a polyester fiber.
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Page/Page column 40
(2008/06/13)
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- New approaches to the synthesis of diphosphine dioxides and hypophosphoric acid esters
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An union >P-O- has been applied as an efficient synthetic precursor of four coordination compounds of the R2P(O)-(O)PR 2 type, namely diphosphine dioxides (R = alkyl, aryl) as well as hypophosphoric acid esters (R = alkoxy, aryloxy), in a one-pot reaction. Furthermore, there were elaborated some mechanistic aspects of the origin of the >P(O)-O-(O)PP-O- and >P(O)X (X= Cl, Br) electrophiles. Attention is focused on the synthesis of the >P(O)-(O)P compounds.
- Nycz, Jacek E.,Musiol, Robert
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p. 310 - 316
(2007/10/03)
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- Hydrolysis of Cyclic Phosphites/Phosphoramidites and Its Inhibition-Reversible Cyclization of Acyclic Phosphonate Salts to Cyclic Phosphites
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Hydrolysis of cyclic phosphites/phosphoramidites (OCH2- CRR′CH2O)PX [X = OPh (1), NMe2 (2)] in the presence of intentionally added water is effectively inhibited by using simple additives such as KF, K2CO3, Et3N, and molecular sieves. Among these, K2CO3 gave the best results. Cyclic H-phosphonates (OCH2CRR′CH2O)P(O)H (3), which are the tautomeric forms of the phosphites (OCH2CRR′CH 2O)P(OH), undergo facile hydrolysis in the presence of aqueous amines to give the acyclic phosphonate salts [H2NMe2] +[(HOCH2CRR′CH2O)P(O)-(H)(O-)] (4) that can be reverted back to 3 upon simple heating. Interestingly, competitive reactions of (OCH2CRR′CH2O)PX [X = Cl (I-III), NMe2 (2)] with phenol and water in the presence of K 2CO3 led only to the phenoxy derivatives and not to the hydrolysis products.
- Satish Kumar,Kumaraswamy, Sudha,Said, Musa A.,Kumara Swamy
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p. 925 - 928
(2013/09/05)
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- A two step synthesis of 2-oxo-2-vinyl 1,3,2-dioxaphospholanes and -dioxaphosphorinanes
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The title compounds are prepared via a two step procedure involving a transesterification between a diol and diethyl phosphite followed by a palladium-catalyzed coupling of the so-obtained cyclic phosphite with vinyl bromide. Theoretical DFT calculations have been performed on phosphonate and phosphite anions models in order to estimate stereoelectronic effects in five-membered and six-membered ring compounds.
- Maffei, Michel,Buono, Gérard
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p. 8821 - 8825
(2007/10/03)
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- Reductive cleavage of the halogen-phosphorus, oxygen-phosphorus and phosphorus-phosphorus bonds with alkali metals
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The reduction of phosphorus acid chlorides as well as hypophosphates, pyrophosphates and mixed P(III)-P(V) anhydrides with alkali metals (Li, Na, K) in NH3 liq. / THF solution and potassium naphthalenide was investigated. It was found that this type of phosphorus compounds easily undergo reduction: a) >P(O)Cl to >P(O)H; b) >P(O)P(O)P(O)H; c) >P(O)-O-P(O)P(O)OH and >P(O)H; d) >P(O)-O-PP(O)O- and >P-. The results of our experiments strongly suggest that the mixed P(III)-P(V) anhydride is reduced by potassium naphthalenide in THF with the cleavage of the P(III)-oxygen bond.
- Nycz, Jacek,Rachon, Janusz
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- Chlorophosphonates: Inexpensive precursors for stereodefined chloro- substituted olefins and unsymmetrical disubstituted acetylenes
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New chlorophosphonates bearing a 1,3,2-dioxaphosphorinane ring which are useful for the stereospecific synthesis of 5-chlorofurfuryl substituted olefins and chloro-substituted dienes have been obtained by an easy, inexpensive route. The utility of some of these in the synthesis of ferrocenyl- and anthracenyl-substituted unsymmetrical acetylenes has been explored. The structures of the phosphonates (OCH2CMe2CH2O)P(O)CH2(C4H2ClO) (4) and (OCH2CMe2CH2O)P(O)(CH=CHCH(Cl)Ph (7) have been determined; in addition, the stereochemistry of (5-chlorofurfuryl)CH=CH(4-ClC6H4) (13b) and 2,4- Cl2C6H3-CH=CH-CH=C(Ph)Cl (14a) is unambiguously proved by the X-ray structure determination.
- Muthiah,Praveen Kumar,Aruna Mani,Kumara Swamy
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p. 3733 - 3737
(2007/10/03)
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- Cyclic phosphorus containing flame retardant compounds
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Certain (1,3,2-dioxaphosphorinanemethan) amine compounds, which are useful as flame retardant compounds, are disclosed. The compounds are particularly useful in polyurethane compositions.
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- Synthesis and reactivity of hydrolysis products of cyclic phosphites with amino substituents
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Hydrolysis of several cyclic aminophosphites are discussed and compared with that of cyclic chloro/phenoxy phosphites.An X-ray structure of a hydrolysis product, (C6H11NH3)(1+)O(1-)P(O)(H)(2,2'-OC6H4-C6H4OH) has been determined.
- Said, Musa A.,Swamy, K. C. Kumara
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- Reactivity of cyclic arsenites and phosphites: X-ray structures of bis(5,5-dimethyl-1,3,2-dioxarsenan-2-yl) ether and bis(2,4,8,10-tetra-tert-butyl-12H-dibenzodioxarsenocin-6-yl) ether
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Reaction of the chlorophosphite 1 with cyclohexylamine gave the expected product 3 whereas the corresponding chloroarsenite 2 led to the bridged compound 12.When the reaction was performed in the presence of water, 1 gave the expected product 11 whereas 2 gave the oxo-bridged compound 13.The amino phosphite 3 underwent hydrolysis to afford the ring cleaved product 18 whereas the phenoxy phosphite 21 led to the ring preserved compound 11.In contrast, the corresponding phenoxy arsenite 25 gave the oxo-bridged compound 13.Addition of perchloro-o-benzoquinone to the phosphite 23 was highly exothermic and afforded the phosphorane 29; however the corresponding arsenoate 27 reacted very sluggishly at room temperature and when heated gave an uncharacterizable mixture of products.The identity of the title oxy-bridged compounds 13 and 15 obtained here has been confirmed by X-ray structure determination; the six-membered rings in 13 have a 'chair' comformation and the eight-membered rings in 15 have a 'symmetrical anti' conformation.
- Said, Musa A.,Swamy, K. C. Kumara,Veith, M.,Huch, V.
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p. 2945 - 2952
(2007/10/02)
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- Halogen-free cyclic phosphorus-containing flame retardant compounds
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Certain (1,3,2-dioxaphosphorinanemethan) amine compounds, which are useful as halogen-free flame retardant compounds, are disclosed. The compounds are particularly useful in polyurethane compositions.
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- Hydrogen phosphonates and polymer compositions containing them as flame retardants
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The present invention relates to cyclic phosphorus compounds including cyclic hydrogen phosphonates and processes for the preparation thereof. The present invention relates to an improved process for the preparation of cyclic hydrogenphosphonates, which comprises the reaction of phosphorochloridites with formic acid in accordance with the general reaction set forth below: STR1 where R is an alkylene or haloalkylene group of a 1,2-glycol having from two to six carbon atoms, or a 1,3-glycol having from three to eight carbon atoms, and Z is Cl or Br. Ketone and sulfenyl derivatives are also a part of the present invention. The cyclic phosphorus compounds are useful as flame retardants with organic polymers, such a polyurethanes, polyesters and polyamides.
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